Last month, someone attached it to an elm tree - appropriately enough, in San Francisco's Golden Gate Park.

No one knows who put it there, but all sorts of people have been showing up to get a look at it, open it and see if anything or anyone is inside.

It's been called "the elf tree", the "fairy tree", the "gnome tree" and in that spirit of imagination some people have put hand-written notes or tiny pastries inside.

As one youngster told NBC (Bay Area) in the video below, "there's a bunch of like notes and stuff... it's like a little house."

The Atlantic said it "looked to be the work of an expert carpenter: lustrous, burnt-orange wood with a beautiful lacquer, perfectly fitted to the natural gap in the tree it protected. Two metal hinges made certain no nut-crazed squirrels were going to knock this baby down."

A San Francisco blogger, Sarah Bacon, told ABC News "When I see the door, I think of the word 'delight... when people talk about walking by it, it makes their day a little happier because it's unexpected."

And a supervisor with the city's parks department told NBC there were plans to remove the door.

Then, the other day, the fun ended. The door was gone. Bacon told The Atlantic "Somebody took it. I don't know. People are jerks."

Photo: Tony Perry via Richmond District of San Francisco Blog

Turns out, the parks department took it away saying it was hurting the tree. But after a number of complaints, ABC News says they put in a new door.

Still, officials say eventually the door has to go because the bolts can damage the tree. There's no word on when it will be removed for good.

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